In DE 195 14 534 C2 and EP 1 113 755 B1 catching snares are described, which enable the extraction of objects out of a human or animal body by a minimal-invasive procedure. These devices each have a snare of shape-memory material, which can be put around an object to be extracted. If the object to be caught is enclosed by the snare, the snare is tightened, whereby the object is held by the snare and the object can be extracted. Using such catching snares, objects, in particular fragments of catheters or of guide wires, can be caught in many different directions. The requirement for the catching is that the snare can be laid around the object. For this purpose the object needs an accessible end, over which end the snare can be put. Objects, which ends are not accessible in the following referred to as non-probable, cannot be extracted by using these catching snares.
Probable in the sense of the invention therefore means that an object to be caught is catchable by the catching snare. For this purpose the object needs an accessible end, which end can be grasped by the snare respectively over which end the snare can be laid. The snare is tightened so that the object is enclosed by the snare firmly. By withdrawing the snare respectively the snare device, the object can be extracted out of the human or animal body. The term “probable” is used in the following in the aforementioned matter.
Furthermore, EP 2 052 688 B2 and DE 10 2006 053 448 A1 disclose snare devices, which have a locking wire, which can be pushed through the snare of the snare device to catch an object between a part of the snare and the locking wire extending through the snare. Using such snare devices objects can be caught, which ends are non-probable. The snare is positioned besides the object to be caught and the locking wire encloses the object on the opposite side of the object, wherein the locking wire engages with the snare, so that the snare and the locking wire surround the object. The object is caught and can be extracted. For such snare devices it is disadvantageous that the hollow elements used with these snare devices have a large diameter, because these snare devices have in addition to the snare a locking wire.
The daily clinical routine has shown that situations, in which ends of objects to be extracted are non-probable are relatively common. This applies to about every tenth procedure. By using a so-called pigtail catheter, which has to be inserted separately, it can be tried to hook the end of the pigtail catheter to the object, for instance a fragment of a catheter, and to execute a pulling motion afterwards so that it is maybe possible to probe the object by moving the end of the object in an open area. The open area can be for example provided by an adjacent vein or a body orifice.
To catch or extract objects, whose ends are non-probable, from the prior art particularly for this application developed pincers respectively special catching snares are known for the objects. These special instruments are exclusively designed for the aforementioned application for objects with non-probable ends. They have special hooks respectively hook-shaped snares, with which the object can be hooked and a fixation of the object by a locking wire can be done afterwards. The locking wire interlaces between the object and the hook-shaped snare so that the object is locked and can be retrieved.
The solutions known from the prior art have the disadvantage that these special instruments for catching of objects with non-probable ends are used only after the catching with conventional snare devices is failed, thus an object with non-probable ends is on hand. Therefore, at first, the conventional snare device has to be removed from the human or animal body and the special instrument has to be inserted separately. Here from derives another disadvantage, which is based on the fact that the caliber of the special instrument is larger than the caliber of the conventional snare device. This enlarges the puncture site, which can lead to complications at the puncture site. The consequence can be the development of thrombosis and/or of hardly stoppable secondary bleedings.
Based on the aforementioned prior art it is the object of the invention to enhance the capability of the known snare devices, in particular to provide the possibility to catch objects with non-probable ends in addition to catch object with probable ends.